Accelerated Sequential Deposition Reaction via Crystal Orientation Engineering for Low-Temperature,High-Efficiency Carbon-Electrode CsPbBr_(3) Solar Cells

Low-temperature,ambient processing of high-quality CsPbBr_(3)films is demanded for scalable production of efficient,low-cost carbon-electrode perovskite solar cells(PSCs).Herein,we demonstrate a crystal orientation engineering strategy of PbBr_(2)precursor film to accelerate its reaction with CsBr precursor during two-step sequential deposition of CsPbBr_(3)films.Such a novel strategy is proceeded by adding CsBr species into PbBr_(2)precursor,which can tailor the preferred crystal orientation of PbBr_(2)film from[020]into[031],with CsBr additive staying in the film as CsPb_(2)Br_(5)phase.Theoretical calculations show that the reaction energy barrier of(031)planes of PbBr_(2)with CsBr is lower about 2.28 eV than that of(O2O)planes.Therefore,CsPbBr_(3)films with full coverage,high purity,high crystallinity,micro-sized grains can be obtained at a low temperature of 150℃.Carbon-electrode PSCs with these desired CsPbBr_(3)films yield the record-high efficiency of 10.27%coupled with excellent operation stability.Meanwhile,the 1 cm^(2)area one with the superior efficiency of 8.00%as well as the flexible one with the champion efficiency of 8.27%and excellent mechanical bending characteristics are also achieved.

晋升公平概念及效用机制的探索——一项质性研究

晋升选拔是组织人力资源开发的重要途径,对员工价值实现和职业发展至关重要。员工对晋升事件的公平判断会影响个人绩效和组织绩效,而现有研究对晋升公平缺乏关注,鲜有研究对晋升公平的理论进行探索和建构,因此本研究的目的是探索晋升公平的概念及效用机制。基于组织公平、甄选公平和晋升公平的文献回顾,本研究整合扎根理论和叙事研究方法,分析了51名企事业单位员工晋升经历的访谈资料,澄清了晋升公平的概念,并构建其影响员工行为的效用机制模型。具体研究发现:晋升公平不仅包括晋升结果公平、晋升程序公平和晋升互动公平,还包括晋升机会公平;晋升公平会引发员工的情绪变化(积极情绪、消极情绪和情绪耗竭)和认知变化(基于组织的自尊、感知的义务、组织信任和自我反思),进而改变员工—组织关系(组织认同和组织承诺)、工作态度(工作满意度和投入度)及工作动机(未来晋升动机),最终影响员工在一般管理情境和中国管理情境中的接近和回避行为(如离职/转岗、沉默行为、拉关系行为和合作行为等);晋升公平影响员工心理和行为时会受到员工个体因素(心理预期、自我效能感、儒家传统价值观)和情境因素(领导安慰和补偿、未来发展空间)的制约。本研究丰富了晋升公平的概念内涵,全面构建了候选者对晋升公平的认知、情感和行为反应的理论模型,指出了晋升公平的“黑暗面”,凸显了中国文化背景下候选者晋升公平反应的特征,启发管理者在了解员工晋升公平感受及其反应的基础上采取应对措施,优化晋升管理实践。

Application of nano-patterned InGaN fabricated by selfassembled Ni nano-masks in green InGaN/GaN multiple quantum wells

The nano-patterned InGaN film was used in green InGaN/GaN multiple quantum wells(MQWs)structure,to relieve the unpleasantly existing mismatch between high indium content InGaN and GaN,as well as to enhance the light output.The different self-assembled nano-masks were formed on InGaN by annealing thin Ni layers of different thicknesses.Whereafter,the InGaN films were etched into nano-patterned films.Compared with the green MQWs structure grown on untreated InGaN film,which on nano-patterned InGaN had better luminous performance.Among them the MQWs performed best when 3 nm thick Ni film was used as mask,because that optimally balanced the effects of nano-patterned InGaN on the crystal quality and the light output.

基于效应维度理论的社会治理路径研究

当前,我国正经历改革开放以来的又一个发展机遇期,随着全面深化改革步伐的推进,政治生态、经济水平和社会环境都呈现出长足的进步,但是转型期的阵痛同样明显,集中在社会领域则多表现为公共危机事件的频发与多元主体协同治理能力的不足。本文的逻辑起点正是基于传统治理模式的瓶颈与构建效应维度社会治理机制的需要。并从标本兼治的思路与社会实践出发,提出长短效应维度理论,探索构建多元社会主体协同治理格局,综合运用多学科交叉的研究方法,从而探究一个基于效应维度理论的社会治理路径,以期达到“强政府–强社会”的社会治理格局目标。

A review of the most recent progresses of state-of-art gallium oxide power devices

Until very recently, gallium oxide(Ga_2O_3) has aroused more and more interests in the area of power electronics due to its ultra-wide bandgap of 4.5–4.8 eV, estimated critical field of 8 MV/cm and decent intrinsic electron mobility limit of250 cm2/(V·s), yielding a high Baliga's figures-of-merit(FOM) of more than 3000, which is several times higher than GaN and SiC.In addition to its excellent material properties, potential low-cost and large size substrate through melt-grown methodology also endows β-Ga_2O_3 more potential for future low-cost power devices. This article focuses on reviewing the most recent advances ofβ-Ga_2O_3 based power devices. It will be starting with a brief introduction to the material properties of β-Ga_2O_3 and then the growth techniques of its native substrate, followed by the thin film epitaxial growth. The performance of state-of-art β-Ga_2O_3 devices, including diodes and FETs are fully discussed and compared. Finally, potential solutions to the challenges of β-Ga_2O_3 are also discussed and explored.

Optimizing the Performance of CsPbI3-Based Perovskite Solar Cells via Doping a ZnO Electron Transport Layer Coupled with Interface Engineering

Interface engineering has been regarded as an effective and noninvasive means to optimize the performance of perovskite solar cells(PSCs).Here,doping engineering of a ZnO electron transport layer(ETL)and CsPbI3/ZnO interface engineering via introduction of an interfacial layer are employed to improve the performances of CsPbI3-based PSCs.The results show that when introducing a TiO2 buffer layer while increasing the ZnO layer doping concentration,the open-circuit voltage,power conversion efficiency,and fill factor of the CsPbI3-based PSCs can be improved to 1.31 V,21.06%,and 74.07%,respectively,which are superior to those of PSCs only modified by the TiO2 buffer layer or high-concentration doping of ZnO layer.On the one hand,the buffer layer relieves the band bending and structural disorder of CsPbI3.On the other hand,the increased doping concentration of the ZnO layer improves the conductivity of the TiO2/ZnO bilayer ETL because of the strong interaction between the TiO2 and ZnO layers.However,such phenomena are not observed for those of a PCBM/ZnO bilayer ETL because of the weak interlayer interaction of the PCBM/ZnO interface.These results provide a comprehensive understanding of the CsPbI3/ZnO interface and suggest a guideline to design high-performance PSCs.

Interfacial Voids Trigger Carbon-Based, All-Inorganic Cs Pb IBr2 Perovskite Solar Cells with Photovoltage Exceeding 1.33 V

A novel interface design is proposed for carbon-based,all-inorganic CsPbIBr2 perovskite solar cells(PSCs)by introducing interfacial voids between TiO2 electron transport layer and CsPbIBr2 absorber.Compared with the general interfacial engineering strategies,this design exempts any extra modification layer in final PSC.More importantly,the interfacial voids produced by thermal decomposition of 2-phenylethylammonium iodide trigger three beneficial e ects.First,they promote the light scattering in CsPbIBr2 film and thereby boost absorption ability of the resulting CsPbIBr2 PSCs.Second,they suppress recombination of charge carriers and thus reduce dark saturation current density(J0)of the PSCs.Third,interfacial voids enlarge built-in potential(Vbi)of the PSCs,awarding increased driving force for dissociating photo-generated charge carriers.Consequently,the PSC yields the optimized e ciency of 10.20%coupled with an open-circuit voltage(Voc)of 1.338 V.The Voc achieved herein represents the best value among CsPbIBr2 PSCs reported earlier.Meanwhile,the non-encapsulated PSCs exhibit an excellent stability against light,thermal,and humidity stresses,since it remains^97%or^94%of its initial e ciency after being heated at 85℃for 12 h or stored in ambient atmosphere with relative humidity of 30–40%for 60 days,respectively.

Design of hierarchical, three-dimensional free-standing single-atom electrode for H2O2 production in acidic media

Electrochemical reduction of molecular O2 to hydrogen peroxide(H2O2)offers a promising solution for water purification and environmental remediation.Here,we design a hierarchical free-standing single-Co-atom(with Co-N4 coordination)electrode for oxygen reduction reaction(ORR)via a two-electron pathway to make H2O2 in acidic media.The current density of the single-Co-atom electrode reached 51 mA/cm2 at 0.1 V vs reversible hydrogen electrode,lasting for more than 10 hours of continuous operation with H2O2 selectivity greater than 80%.Toward practical application,the single-Co-atom electrode was directly used to assemble an electrochemical cell to produce H2O2 at a rate of 676 mol/kgcat/h with a cell voltage of about 1.6 V.

Gallium oxide: promise to provide more efficient life

Despite being the long-time mainstream semiconductor for both logic and power devices, Silicon is now facing its dilemma and limitation of scalability and material potential.Especially for power devices, people are demanding escalating efficiency with higher blocking voltage while its power consumption and heat generation are less. Constrained by its narrow bandgap of 1.14 eV, Silicon only has a critical breakdown field(E_c) of 0.3 MV/cm, yielding a Baliga figureof-merit(BFOM = ε×μ× E_c^3) of unity when normalized to itself. It is hence required that the dominating factor E_c should be as high as possible such that the BFOM will be hundreds or even thousands of times when compared to Silicon so as to minimize the conduction loss. Beta-Gallium Oxide(β-Ga_2O_3) with decent μ of 250 cm2/Vs, ultra-wide bandgap of4.8 eV and high critical E_c of 8 MV/cm, yielding a superior high BFOM of more than 3000. Therefore, system made withβ-Ga_2O_3 can be thinner, lighter and capable of handling more power than the one with Silicon. In addition, low-cost and large size substrate through melt-grown method endows β-Ga_2O_3 more potentials as cost-effective power devices. After resolving the low thermal conductivity issue,unipolar devices made with ultra-wide bandgap β-Ga_2O_3 are promised to make power transition and our life more efficient.

Ultrahigh-rate and high-frequency MXene micro-supercapacitors for kHz AC line-filtering

Harnessing energy from the environment promotes the rapid development of micro-power generators and relevant power management modules of alternating current (AC) line-filtering to obtain a stabilized direct current (DC) output for storage and use. Micro-supercapacitors (MSCs) with miniaturized volume and high-frequency response are regarded as a critical component in filtering circuits for microscale power conversion. Here, we reported the fabrication of the wafer-sized planar MSCs (M-MSCs) based on 2D Ti_(2)C_(2)T_(6) MXene using a photolithography technique. The M-MSCs exhibited an areal capacitance of 153 μF cm^(-2) and a frequency characteristic (f_(0)) of 5.6 k Hz in aqueous electrolyte. Moreover, by employing suitable ionic liquid as electrolyte, the voltage window was expanded to 2 V and the f_(0) could be pushed to 6.6 k Hz relying on the electrical double-layer mechanism and lower adsorption energy while maintaining quasi-rectangular cyclic voltammogram curves at 5000 V s^(-1). Furthermore, the integrated MSCs pack was constructed and exhibited excellent rectifying ability by filtering various highfrequency 5000 Hz AC signals with different waveforms into stable DC outputs. Such ultrahigh-rate and high-voltage M-MSCs module for k Hz AC line-filtering would be potentially integrated with customizable electronics to realize on-chip rectifiers in high-density integrated circuit.

Recent progress of electrochemical reduction of CO_(2)by single atom catalysts

Powered by electricity from renewable energies,electrochemical reduction of CO_(2)could not only efficiently alleviate the excess emission of CO_(2),but also produce many kinds of valuable chemical feedstocks.Among various catalysts,single atom catalysts(SACs)have attracted much attention due to their high atom utilization efficiency and expressive catalytic performances.Additionally,SACs serve as an ideal platform for the investigation of complex reaction pathways and mechanisms thanks to their explicit active sites.In this review,the possible re-action pathways for the generation of various products(mainly C1 products for SACs)were firstly summarized.Then,recent progress of SACs for electrochemical reduction of CO_(2)was discussed in aspect of different central metal sites.As the most popular and efficient coordination modulation strategy,introducing heteroatom was then reviewed.Moreover,as an extension of SACs,the development of dual atom catalysts was also briefly discussed.At last,some issues and challenges regarding the SACs for CO_(2)reduction reaction(CO_(2)RR)were listed,followed by corresponding suggestions.

Secondary crystallization strategy for highly efficient inorganic CsPbI_(2)Br perovskite solar cells with efficiency approaching 17%

Inorganic CsPbI_(2) Br perovskite solar cells(PSCs) have a tremendous development in last few years due to the trade-off between the excellent optoelectronic properties and the relatively outstanding stability.Herein,we demonstrated a strategy of secondary crystallization(SC) for CsPbI_(2) Br film in a facile planar n-i-p structure(ITO/ZnO-SnO_(2)/CsPbI_(2) Br/Spiro-OMeTAD/Ag) at low-temperature(150℃).It is achieved through the method of post-treatment with guanidinium bromine(GABr) atop annealed CsPbI_(2) Br film.It was found that the secondary crystallization by GABr can not only regulate the crystal growth and passivate defects,but also serve as a charge collection center to effectively collect photogenerated carriers.In addition,due to the excess Br ions in GABr,the formation of the Br-rich region at the CsPbI_(2) Br perovskite surface can further lower the Fermi level,leading to more beneficial band alignment between the perovskite and the hole transport layer(HTL),while the phase stability was also improved.As a result,the champion cell shows a superb open-circuit voltage(V_(oc)) of 1.31 V,a satisfactory power conversion efficiency(PCE) of 16.97% and outstanding stabilities.As far as we know,this should be one of the highest PCEs reported among all-inorganic CsPbI_(2) Br based PSCs.

Chemoattractive capacity of different lengths of nerve fragments bridging regeneration chambers for the repair of sciatic nerve defects

A preliminary study by our research group showed that 6-mm-long regeneration chamber bridging is equivalent to autologous nerve transplantation for the repair of 12-mm nerve defects. In this study, we compared the efficacy of different lengths （6, 8, 10 mm） of nerve fragments bridging 6-mm regeneration chambers for the repair of 12-mm-long nerve defects. At 16 weeks after the regeneration chamber was implanted, the number, diameter and myelin sheath thickness of the regenerated nerve fibers, as well as the conduction velocity of the sciatic nerve and gastrocnemius muscle wet weight ratio, were similar to that observed with autologous nerve transplantation. Our results demonstrate that 6-, 8-and 10-mm-long nerve fragments bridging 6-mm regeneration chambers effectively repair 12-mm-long nerve defects. Because the chemoattractive capacity is not affected by the length of the nerve fragment, we suggest adopting 6-mm-long nerve fragments for the repair of peripheral nerve defects.

Reveal the large open-circuit voltage deficit of all-inorganic CsPbIBr_(2) perovskite solar cells

Due to excellent thermal stability and optoelectronic properties, all-inorganic perovskite is one of the promising candidates to solve the thermal decomposition problem of conventional organic–inorganic hybrid perovskite solar cells(PSCs),but the larger voltage loss(V_(loss)) cannot be ignored, especially CsPbIBr_(2), which limits the improvement of efficiency. To reduce V_(loss), one promising solution is the modification of the energy level alignment between the perovskite layer and adjacent charge transport layer(CTL), which can facilitate charge extraction and reduce carrier recombination rate at the perovskite/CTL interface. Therefore, the key issues of minimum V_(loss) and high efficiency of CsPbIBr_(2)-based PSCs were studied in terms of the perovskite layer thickness, the effects of band offset of the CTL/perovskite layer, the doping concentration of the CTL, and the electrode work function in this study based on device simulations. The open-circuit voltage(V_(oc)) is increased from 1.37 V to 1.52 V by replacing SnO_(2) with ZnO as the electron transport layer(ETL) due to more matching conduction band with the CsPbIBr;layer.

Superior Pseudocapacitive Storage of a Novel Ni3Si2/ NiOOH/Graphene Nanostructure for an All‑Solid‑State Supercapacitor

Recent developments in the synthesis of graphene-based structures focus on continuous improvement of porous nanostructures,doping of thin films,and mechanisms for the construction of threedimensional architectures.Herein,we synthesize creeper-like Ni3Si2/NiOOH/graphene nanostructures via low-pressure all-solid meltingreconstruction chemical vapor deposition.In a carbon-rich atmosphere,high-energy atoms bombard the Ni and Si surface,and reduce the free energy in the thermodynamic equilibrium of solid Ni–Si particles,considerably catalyzing the growth of Ni–Si nanocrystals.By controlling the carbon source content,a Ni3Si2 single crystal with high crystallinity and good homogeneity is stably synthesized.Electrochemical measurements indicate that the nanostructures exhibit an ultrahigh specific capacity of 835.3 C g^−1(1193.28 F g^−1)at 1 A g^−1;when integrated as an all-solidstate supercapacitor,it provides a remarkable energy density as high as 25.9 Wh kg^−1 at 750 W kg^−1,which can be attributed to the freestanding Ni3Si2/graphene skeleton providing a large specific area and NiOOH inhibits insulation on the electrode surface in an alkaline solution,thereby accelerating the electron exchange rate.The growth of the high-performance composite nanostructure is simple and controllable,enabling the large-scale production and application of microenergy storage devices.

Double Side Interfacial Optimization for Low-Temperature Stable CsPbI_(2)Br Perovskite Solar Cells with High Efficiency Beyond 16%

CsPbI_(2)Br perovskite solar cells have achieved rapid development owing to their exceptional optoelectronic properties and relatively outstanding stability.However,open-circuit voltage(Voc)loss caused by band mismatch and charge recombination between perovskite and charge transporting layer is one of the crucial obstacles to further improve the device performance.Here,we proposed a bilayer electron transport layer ZnO(bottom)/SnO_(2)(top)to reduce the Voc loss(Eloss)and promote device Voc by ZnO insert layer thickness modulation,which could improve the efficiency of charge carrier extraction/transfer and suppress the charge carrier recombination.In addition,guanidinium iodide top surface treatment is used to further reduce the trap density,stabilize the perovskite film and align the energy levels,which promotes the fill factor,short-circuit current density(Jsc),and stability of the device.As a result,the champion cell of double-side optimized CsPbI_(2)Br perovskite solar cells exhibits an extraordinary efficiency of 16.25%with the best Voc as high as 1.27 V and excellent thermal and storage stability.

Germanium-tin alloys： applications for optoelectronics in mid-infrared spectra

We summarize our work of the optoelectronic devices based on Germanium-tin （GeSn） alloys assisted with the Si3N4liner stressor in mid-infrared （MIR） domains. The device characteristics are thoroughly analyzed by the strain distribution,band structure, and absorption characteristics. Numerical and analytical methods show that with optimal structural pa-rameters, the device performance can be further improved and the wavelength application range can be extended to 2~5 μm in the mid-infrared spectra. It is demonstrated that this proposed strategy provides an effective technique for the strained-GeSn devices in future optical designs, which will be competitive for the optoelectronics applications in mid-infrared wavelength.

Multifunctional solar-blind ultraviolet photodetectors based on p-PCDTBT/n-Ga_(2)O_(3)heterojunction with high photoresponse

Solar-blind ultraviolet(UV)photodetectors based on p-organic/n-Ga_(2)O_(3) hybrid heterojunctions have attracted extensive attention recently.Herein,the multifunctional solar-blind photodetector based on p-type poly[N-90-heptadecanyl-2,7-carbazole-alt-5,5-(40,70-di-2-thienyl-20,10,30-benzothiadiazole)](PCDTBT)/n-type amorphous Ga_(2)O_(3)(a-Ga_(2)O_(3))is fabricated and investigated,which can work in the phototransistor mode coupling with self-powered mode.With the introduction of PCDTBT,the dark current of such the a-Ga_(2)O_(3)-based photodetector is decreased to 0.48 pA.Meanwhile,the photoresponse parameters of the a-Ga_(2)O_(3)-based photodetector in the phototransistor mode to solar-blind UV light are further increased,that is,responsivity(R),photo-detectivity(D*),and external quantum efficiency(EQE)enhanced to 187 A W^(-1),1.3×10^(16) Jones and 9.1×10^(4)% under the weak light intensity of 11μW cm^(-2),respectively.Thanks to the formation of the built-in field in the p-PCDTBT/n-Ga_(2)O_(3) type-Ⅱ heterojunction,the PCDTBT/Ga_(2)O_(3) multifunctional photodetector shows self-powered behavior.The responsivity of p-PCDTBT/n-Ga_(2)O_(3) multifunctional photodetector is 57.5 mA W^(-1) at zero bias.Such multifunctional p-n hybrid heterojunction-based photodetectors set the stage for realizing high-performance amorphous Ga_(2)O_(3) heterojunction-based photodetectors.

Nanotherapeutics targeting autophagy regulation for improved cancer therapy

The clinical efficacy of current cancer therapies falls short,and there is a pressing demand to integrate new targets with conventional therapies.Autophagy,a highly conserved self-degradation process,has received considerable attention as an emerging therapeutic target for cancer.With the rapid development of nanomedicine,nanomaterials have been widely utilized in cancer therapy due to their unrivaled delivery performance.Hence,considering the potential benefits of integrating autophagy and nanotechnology in cancer therapy,we outline the latest advances in autophagy-based nanotherapeutics.Based on a brief background related to autophagy and nanotherapeutics and their impact on tumor progression,the feasibility of autophagy-based nanotherapeutics for cancer treatment is demonstrated.Further,emerging nanotherapeutics developed to modulate autophagy are reviewed from the perspective of cell signaling pathways,including modulation of the mammalian target of rapamycin(mTOR)pathway,autophagy-related(ATG)and its complex expression,reactive oxygen species(ROS)and mitophagy,interference with autophagosome-lysosome fusion,and inhibition of hypoxia-mediated autophagy.In addition,combination therapies in which nano-autophagy modulation is combined with chemotherapy,phototherapy,and immunotherapy are also described.Finally,the prospects and challenges of autophagy-based nanotherapeutics for efficient cancer treatment are envisioned.

无真空、低成本Mist-CVD外延制备高质量单晶NiO/Ga_(2)O_(3)p-n异质结与器件

在氧化镓(Ga_(2)O_(3))材料p型掺杂困难的背景下,Ga_(2)O_(3)p-n异质结器件在氧化镓器件的应用中起着重要作用.因此,寻找一种高效、经济的制备方法制备Ga_(2)O_(3)异质结对器件应用具有重要意义.在这项工作中,我们成功基于低成本、无真空的雾化学气相沉积(Mist-CVD)外延制备了单晶氧化镍(NiO)和β-Ga_(2)O_(3)异质结.其中,NiO(111)和β-Ga_(2)O_(3)(-201)的XRD摇摆曲线半高宽分别为0.077°和0.807°.NiO与β-Ga_(2)O_(3)之间的能带表现为Ⅱ型异质结构.基于此异质结,我们制备了准垂直器件,器件具有明显的p-n结整流特性,反向击穿电压为117 V.本工作为β-Ga_(2)O_(3)异质p-n结的制备提供了一种低成本、高质量的方法.